GCSE Biology Required Practical: Measuring Population in a Habitat
Key Stage 4
Meaning
Estimate the size of a population of a species within a habitat using sampling techniques and investigate a factor affecting population size.
Method
Estimate the population of a species within a habitat using random sampling.
- Gently throw a quadrat to fall in a random position on a field of grass.
- Count the number of daisies within the quadrat.
- Repeat steps 1 and 2 ten times.
- Calculate the mean number of daisies.
- Use the following equation to estimate the number of daisies in the field:
- Estimated population = \(\tfrac{area sampled}{total area}\) x number of daisies
Investigate the effect of a factor on plant distribution using a transect.
- Stretch a 30m tape from the base of a tree out into an open area of field. This will be the transect.
- Place a quadrat at 0m on the transect and count the number of daisies within the quadrat.
- Repeat step 2 six times moving the quadrat 5m further along the transect each time.
- At each location you may measure the light intensity, soil hydration or soil pH to determine if this factor affects the abundance of daisies.